Research Publications
The Impact of Head Movements on Binaural Externalization Across Varying Demographics
Author(s): Treanor, Garrett
Publication Date: Pending Publication (2025)
Abstract: With headphone technologies advancing at an evermore rapid pace, the commercial and investigative desire to evaluate their efficacy in preparation for broad adoption is quickly becoming a necessity. Despite this, very few, if any, published works have evaluated the impact that demographic information has on various externalization factors, including head-tracking, and this is compounded by the comparatively small population sizes of the studies that have been published, leading to significant findings with unknown applicability. Subjective listening tests were conducted among 23 subjects representing multiple demographic groups in terms of age, musical experience, and binaural experience, in order to evaluate the impact of head-tracking on binaural externalization and the influence that differing demographics may have. The findings of this study indicate that head-tracked head-movements may play a larger role in preventing binaural externalization collapse, rather than increasing or improving perceived binaural externalization, and that there is no statistically significant difference in perception of externalization of either speech or broadband noise between differing age groups, musical experience groups, or binaural experience groups, but that there is a statistically significant difference in perception of coloration between groups of differing musical experience.
Subjective Evaluation of Binaural Enhancement Methods
Author(s): Jot, Jean-Marc; Ranade, Shaunak; Treanor, Garrett; Harel, Daphna; Roginska, Agnieszka
Publication Date: Pending Publication (2025)
A Subjective Evaluation Methodology for Binaural Enhancement
Author(s): Jot, Jean-Marc; Treanor, Garrett; Ranade, Shaunak; Li, Zhinuo; Harel, Daphna; Roginska, Agnieszka
Publication Date: August 18, 2025
Link: https://aes2.org/publications/elibrary-page/?id=22951
Abstract: Binaural reproduction techniques are essential for personal spatial audio reproduction over headphones, earbuds, head-mounted displays, or loudspeaker arrays. In addition to lateral localization and perceived scene width, the success metrics of binaural reproduction methods include: elevation fidelity, front/back distinction (unambiguous localization of sounds presented in front or back), externalization (the impression that the reproduced sound originates from outside of the listener’s head), and timbre reproduction (minimizing artificial room tone or spectral coloration). In this study, we propose a methodology for the subjective evaluation and performance comparison of binaural reproduction enhancement methods. It aims to consistently elicit these subjective attributes in view of the wide variation of audio source types, playback conditions, and signal processing techniques that differentiate binaural reproduction circumstances in consumer applications. We report on some preliminary results of an experimental survey utilizing this methodology, where three binaural rendering methods are compared in a single-source spatialization scenario and a controlled headphone listening environment, without artificial reverberation, listener-dependent personalization, head movement compensation, or accompanying visual cues.
Preventing Binaural Externalization Collapse Without the Use of Individualized Head-Related Transfer Functions
Author(s): Treanor, Garrett
Type: Masters thesis
Defense Date: April 22, 2025
Abstract: With headphone technologies advancing at an evermore rapid pace, the commercial and academic desire to determine their efficacy in preparation for broad adoption is quickly becoming a necessity. Of these developments, there has been a growing demand to understand and develop techniques for improving binaural externalization. Despite this, virtually all published works evaluating binaural externalization techniques and factors are subject to some number of shortcomings, whether by omitting crucial information, surveying small-scale populations, employing overly-narrow methodologies, or any combination of the three. These limitations prevent valuable comparative analyses from being made and complicate the process of reproducing the presented investigation, resulting in publications reporting significant findings with ultimately unknown applicability. With considerations for future comparative analysis, 23 subjects representing multiple demographic groups in terms of age, musical experience, and binaural experience were secured with head-tracking devices and presented with both speech and broadband stimuli under varying experimental conditions before evaluating their perception of externalization and spectral coloration of the stimuli in order to evaluate the impact of head-tracked movements on perceived externalization of binaural sound sources. The findings of this investigation indicate that head-tracked head-movements may play a larger role in preventing binaural externalization collapse, rather than increasing or improving perceived binaural externalization, and that there is no statistically significant difference in perception of externalization or coloration of either speech or broadband noise between differing age groups, musical experience groups, or binaural experience groups.
Exploring Immersive Recording and Reproduction Methods for Pipe Organs
Author(s): Treanor, Garrett; Luo, Jessica; Tsuaye, Jeremy; Songmuang, Parichat; Wu, Yi; Jaimes, Angel; Bobby, Joel; Li, Zhinuo
Publication Date: September 27, 2024
Link: https://aes2.org/publications/elibrary-page/?id=22728
Abstract: The pipe organ is often underrepresented in classical music recordings, particularly in immersive audio formats. This paper explores a novel approach to recording and reproducing the organ for immersive formats using a modified Bowles Array. Key considerations for immersive recording and reproduction are examined, including the balance between aestheticism and realism, the role of the LFE channel, and the acoustic characteristics of the recording and reproduction environments, as well as the instrument itself. The findings aim to enhance the immersive audio experience of pipe organ music and provide valuable insights for developing standards in immersive recording and reproduction methods for pipe organ performances.
The Impact of Height Microphone Layer Position on Perceived Realism of Organ Recording Reproduction
Author(s): Luo, Jessica; Treanor, Garrett
Publication Date: September 27, 2024
Link: https://aes2.org/publications/elibrary-page/?id=22692
Abstract: For on-site immersive recordings, height microphones are often placed carefully to avoid a distorted or unrealistic image, with many established immersive microphone arrays placing the height microphones 1.5 m or less above the horizontal layer. However, with an instrument so acoustically symbiotic with its space as the pipe organ, the impact of non-coincident height microphone placement has not previously been explored in-depth. Despite this, the pipe organs radiation characteristics may benefit from non-coincident height microphone placement, providing subjectively improved tone color without sacrificing perceived realism. Subjective listening tests were conducted comparing a pipe organ recording with coincident and non-coincident height microphone positions. The findings of this case study conclude that non-coincident height microphone placement does not significantly impact perceived realism of the immersive organ recording.